What are these bugs?

[ATH]

Saw a bunch on Beech trees in the woods today. Was thinking maybe they are Beech blight aphids in an early life stage. But then I saw a bunch on Red oak and Sugar maple as well...

I didn't have a magnifier to get a better picture...

 

[JD3000]

Send it to Shetlar. Keep him sharp in his retirement...

 

[ATH]

Dave Shetlar's reply:

"These are the aquatic springtails. I noticed them in abundance last weekend when I was doing a forest walk. This species is the same one that is often encountered during the middle of the winter and can be found in abundance on the surface of snow – hence, their other name of “snowflea.” This species feeds on bluegreen algae and I suspect they are on the trunks of trees munching on any algae that may be there."